The Vestige met the Prophet on 4 Rain's Hand 2e582. (4 April 2014, the day the game came out) ... we are now in 2e593

?
According to the UESP web page relating to the 'Oblivion' game ... the Order of the Dragon is an order of knights originally founded by Tiber Septim. Throughout the Empire's history, there have been seven Champions of Cyrodiil, the highest rank in the order, with the seventh being the Hero of Kvatch.
Could the ESO Dragonknights be the precursors of the Order (Tiber Septim reigned from 2e854 to 3a38), we only know them as the Children of the Mundus ... followers of a new martial tradition (another UESP web page)
During the afternoon of Loredas, 6 Sun’s Dawn 2e578 a big piece of Aetherius fell to Nirn. It was the first major piece of Aetherius to fall on Nirn in more than five hundred years. It scattered around the world as millions of shards. It was rapidly documented by Lady Cinnabar of Taneth in her pamphlet Aetherial Fragments that "... when three shards meet, they re-form into a silvery prism by unknown process and confer the power unlocked by the merger to a nearby being." The Order of the Black Worm, commonly known as the Worm Cult, reappeared in Tamriel shortly thereafter and some of its members are avidly searching said shards.
In the last week of First Seed 2e579, an arcane explosion occurred in the Imperial City — a night of storms, and trembling terrain. They named it the "Soulburst". That day Emperor Varen Aquilarios disappeared without a trace. His wife, Clivia Tharn, ascended to the Ruby Throne as Empress Regent under the guidance of the Necromancer Mannimarco. Ushering a time of increased instability within the Empire of Cyrodiil which finally grew into “The Three Banners War”.